How to setup DNS for my VPS account which comes with only 1 static IP ?

Use your domain registrar managed DNS service

1) Change your domain name DNS to the those provided by your registrar.
1) Create a new zone for your domain (eg. yourdomain.tld)
2) Add a A-Record that points to your Server-IP (e.g. A: * / 202.1.1.209)

wait 24~48 hours for the DNS to propagate to the world

Use 3rd party free DNS services.

You need a DNS hosting service provider for your domain.

I recommend you to try out a service like FreeDNS. Free for most use. You can find more free dns providers from google.

1) Register an account at your new dns provider
2) Create a new zone for your domain (eg. yourdomain.tld)
3) Add a A-Record that points to your Server-IP (e.g. A: * / 127.0.0.1)
4) Point your domain to the nameserver’s provided by FreeDNS

wait 24~48 hours for the DNS to propagate to the world